Automatic shifting control device for a bicycle

Abstract

A bicycle features an automatically shifting transmission. The shifting is controlled by a controller. The controller has a number of ranges that comprise a subset of the available gear steps. The operator of the bicycle can select an appropriate range and the controller shifts gears within the range depending upon a preset map of bicycle speeds and gear steps. The operator can select other ranges as desired by upshifting or downshifting. The controller also has at least one cruising mode that decreases the likelihood of inadvertent shifting during operation of the bicycle at speeds within a preset range of speeds. In addition, the controller has an elapse mode that further reduces the number of available gear steps in a range during resumed operation after slowing below a preset speed or stopping.

What is claimed is:  
     
       1. A method of controlling shifting in a bicycle transmission capable of automatic shifting, said method comprising sensing an operating speed of the bicycle, monitoring a period of time between transmission shifts, determining when a preset period of time between transmission shifts has elapsed and recalibrating an upper speed value and a lower speed value for a gear step currently in use. 
     
     
       2. The method of  claim 1  further comprising recalibrating an upper speed value and a lower speed value for all available gear steps when said preset period of time between transmission shifts has elapsed. 
     
     
       3. The method of  claim 1  further comprising calculating an average speed for said preset period of time and recalibration comprises altering said upper speed value and said lower speed value such that said average speed is substantially centered between said upper speed value and said lower speed value. 
     
     
       4. The method of  claim 1  further comprising calculating a speed difference between said upper speed value and said lower speed value, calculating an average speed for said preset period of time, adding half of the speed difference to said average speed to arrive at a replacement upper speed value and subtracting half of the speed difference from said average speed to arrive at a replacement lower speed value. 
     
     
       5. The method of  claim 1 , wherein recalibrating said upper speed value and said lower speed value comprises expanding a range defined between said upper speed value and said lower speed value for all available gear steps. 
     
     
       6. The method of  claim 5 , wherein recalibrating said upper speed value and said lower speed value further comprises reducing a number of available gear steps to accommodate the expansion of ranges for all available gear steps. 
     
     
       7. The method of  claim 1 , wherein recalibrating said upper speed value and said lower speed value comprises expanding a range defined between said upper speed value and said lower speed value for said gear step currently in use. 
     
     
       8. The method of  claim 1 , wherein said period of time between transmission shifts is continuously monitored and said recalibrating occurs after every preset period time has elapsed. 
     
     
       9. The method of  claim 1 , wherein said recalibrating is canceled by a gear shift. 
     
     
       10. The method of  claim 9  further comprising resetting said upper speed value and said lower speed value upon detection of a gear shift. 
     
     
       11. A method of controlling shifting in a bicycle transmission capable of automatic shifting, said method comprising sensing an operating speed of the bicycle, automatically changing gears within a first preset range of gear steps depending upon said operating speed of the bicycle, determining if said operating speed is rapidly reduced below a first threshold operating speed, switching to a second preset range of gear steps when said operating speed is rapidly reduced below said first threshold operating speed, automatically changing gears within said second preset range of gear steps depending upon said operating speed of the bicycle, and said first preset range of gear steps comprising more gear steps than said second preset range of gear steps. 
     
     
       12. The method of  claim 11  further comprising automatically changing gears within said first preset range of gear speeds when said operating speed returns above a second threshold operating speed. 
     
     
       13. The method of  claim 12 , wherein said first threshold operating speed and said second threshold operating speed are the same operating speed. 
     
     
       14. The method of  claim 13 , wherein said first threshold operating speed is an upper operating speed for a lowermost gear step of said first preset range of gear steps. 
     
     
       15. A method of controlling shifting in a bicycle transmission capable of automatic shifting, said method comprising selecting an automatic operating mode, selecting a first preset range of gear steps from a plurality of preset ranges of gear steps, and operating said bicycle transmission among said selected preset range of gear steps. 
     
     
       16. The method of  claim 15  further comprising selecting a second preset range of gear steps from said plurality of preset ranges of gear steps. 
     
     
       17. The method of  claim 16 , wherein said selecting said second preset range of gear steps comprises detecting an output from a slope sensor to determine if a surface over which the bicycle is being operated slopes upward or downward. 
     
     
       18. The method of  claim 16 , wherein said selecting said second preset range of gear steps comprises detecting a position change in a front derailleur. 
     
     
       19. The method of  claim 16 , wherein said selecting said second preset range of gear steps comprises detecting a heart rate of an operator to determine if said detected heart rate exceeds a preset target heart rate. 
     
     
       20. The method of  claim 16 , wherein said selecting said second preset range of gear steps comprises detecting a driving torque upon a crank of said bicycle to determine if said driving torque exceeds a preset driving torque. 
     
     
       21. The method of  claim 16 , wherein said selecting said second preset range of gear steps comprises detecting movement of a first switch. 
     
     
       22. The method of  claim 21 , wherein said plurality of preset ranges of gear steps are incrementally related such that detecting movement of said first switch in a first direction selects said second preset range of gear steps to be incrementally one range higher than said first preset range of gear steps and such that detecting movement of said switch in a second direction selects said second preset range of gear steps to be incrementally one range lower than said first preset range of gear steps.